I\'m not sure whether I need to add an exit button to my app. Is there any point to doing this? And if on exiting one activity or service is not .finish() or closed properly
From a technical perspective, no, you don't need to add a quit button for all the very good reasons listed here.
Unfortunately users aren't informed in this way and regularly drop review scores because they have to 'use a task killer' or 'force close' your app.
It is a regular request and criticism in reviews/feedback for my app. So it may be necessary to appease users.